Document Type : Research Paper
Author
Teacher of Geography at Teaching Center of Imam Jafar Sadeq in Bojnourd
Abstract
The present article aims to investigate causes of flooding in Esfarayen County and introduces different applications of geomorphology in providing structural methods of floodwater management. Considering the present situation, structural methods like canals, bridges and retarding reservoirs are used for introducing flood controlling methods. In order to design these structures, maximum annual instant discharge was calculated using Dakin equation and statistics received from Bidvaz River hydrological station. Then, sections of the buildings and their dimensions were determined for a return period of 5 to 500 years using Manning relation and finally discharge was calculated by multiplying average current velocity to section area. Results indicate that apart from natural factors like precipitation regime, impermeability of formations, drainage density, vegetation poverty and slope, human factors like settlement and development of villages across fans, redirection and integration of waterways, unnecessary arches in canals and ignoring probable maximum precipitation in construction intensify flooding in villages. According to the findings, any changes to the dimensions, types and forms of drainage network must be in accordance with geomorphological theories. Moreover, this subfield of physical geography is especially potential in proposing structural methods for floodwater management.
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